From the document EP 1 310 351 B1 it is known to cast an integrated wind turbine rotor blade in one moulding process using for example a VARTM process. It is furthermore known to add core material such as balsawood or PVC foam in the blade, such as at the trailing edge of the blade, to increase the stability and stiffness of the blade. The purpose of putting core material in the trailing edge of the blade is to build stiffness to this part of the rotor blade.
To integrate for example triangular shaped trailing edge core material it is necessary to establish extra layers of reinforced material around the triangular shaped trailing edge core material and it all is established in between the outer shell layers of the blade composite structure. Hereby a trailing edge “web” is created which helps in transferring forces and creates stiffness between the upper and lower parts of the blade construction. However, one difficulty with this solution is that it is relatively time consuming to lay up the reinforced fibre material around the core material in a proper manner so that the desired construction and properties are achieved.